<div class="panel panel-primary">
  <div class="panel-heading">NgSwitch演示</div>
  <div class="panel-body">
    <div [ngSwitch]="mapStatus">
      <p *ngSwitchCase="0">下载中……</p>
      <p *ngSwitchCase="1">读取中……</p>
      <p *ngSwitchDefault>系统繁忙……</p>
    </div>
  </div>
</div>